Dr. Jason Eberhart-Phillips: Risks of energy drinks to fight fatigue

WITH FINAL EXAM season in full sway, students in Marin and elsewhere may be more tempted to toss down a few so-called energy drinks to boost their attention spans, increase their stamina and feel more awake throughout the day.

Though more costly than regular sodas, highly caffeinated energy drinks are easy to find — and they usually deliver on their promise to ward off droopy eyelids when mental concentration is needed — at least for a while. But in the two years since IJ columnist Dr. Bill Elliott first raised health concerns about these products, controversy about energy drinks has intensified.

Are these beverages harmless, mild stimulants that help students and millions of others who use them every day perform at their best, as the industry claims? Or are they potentially lethal drugs that need far more rigorous regulation to protect young people's health?

Since energy drinks were introduced in the United States just 16 years ago, sales have increased steadily, reaching nearly $9 billion in 2011, according to Beverage Digest, a trade publication. Thanks to aggressive advertising aimed largely at adolescents and young adults, people younger than 35 are thought to comprise the core market.

Years after concerns were raised by the American Academy of Pediatrics and other health authorities, the federal Food and Drug Administration is at last giving energy drinks increased scrutiny. Late last year the agency's own voluntary monitoring system for adverse effects turned up several injuries and deaths that might be associated with the products.

That disclosure was followed this year by an analysis of emergency room data by the Drug Abuse Warning Network that showed a doubling of energy drink-associated emergency room visits between 2007 and 2011, to more than 20,000 visits a year.

San Francisco City Attorney Dennis Herrera has sought to curtail what he has called "irresponsible marketing and business practices" by the largest maker of energy drinks. Citing a "mounting scientific consensus that highly caffeinated energy drinks pose potentially serious health risks to young people," Herrera has sought to compel the Monster Beverage Corp. to lower the caffeine level in its products, to provide warning labels and to cease targeting minors with its marketing.

So how might the high doses of caffeine in energy drinks harm a young person's health?

Effects vary, but people who consume large quantities of caffeine in a short time often experience a quickening of the heart rate and an acute elevation in blood pressure. In some cases, potentially serious disruptions of normal heart rhythm have been reported.

Other circulatory effects include changes in the chemistry of the blood and constriction of blood vessels in the heart, factors that increase the risk of a heart attack in susceptible individuals.

Recent case reports have also linked energy drinks to the onset of seizures. Typically, the seizures have ceased when consumption of energy drinks was halted. Other neurologic symptoms reported by young people with high caffeine intake include nervousness, anxiety, jitteriness and headache.

Young people, who generally have less experience with caffeine, appear to be more sensitive to many of its effects, according to a letter sent to the FDA by 18 leading scientists. In the letter the scientists mentioned loss of sleep at night, poor academic performance, aggressive behavior and social maladjustment as outcomes sometimes linked to high caffeine consumption among young people.

The scientists also refuted claims made by some energy drink manufacturers that certain additives in their products may actually improve physical or cognitive performance.

The combined effects of alcohol and energy drinks are particularly worrisome. A survey published by University of Michigan researchers in 2011 noted that 26 percent of high school seniors had consumed alcoholic beverages together with caffeine in the past year. Among college students, the rate for mixing energy drinks with alcohol was as high as 54 percent in an average month, according to a survey published in the Nutrition Journal in 2007.

By offsetting the sedating effects of alcohol, the caffeine in energy drinks reduces the sensation of intoxication. Without the usual cues of inebriation, judgment is impaired, leaving drinkers more prone to engage in risky behaviors, such as drunk driving, than if they had been drinking alcohol alone. The reduced sensation of intoxication also leads to more alcohol consumption, impairing judgment further.

As the evidence against energy drinks mounts, it may be time to limit our consumption and that of our teenagers and children.

But why all the fuss about caffeine in energy drinks? After all, coffee also contains caffeine — some brands more than others — and so do regular sodas. Three reasons account for the concern:

 Many energy drinks have more caffeine per can than in a cup of all but the most highly caffeinated brands of coffee, and nearly all have at least twice as much caffeine as regular sodas. With 200 milligrams of caffeine or more in a single can, the strongest energy drinks provide double the maximum daily intake of caffeine recommended for adolescents by the American Academy of Pediatrics.

 Coffee is a bitter drink that is typically served hot and sipped slowly. Energy drinks are served cold and are typically consumed much faster and in larger quantities. In the labeling on its cans, one leading brand encourages consumers to "chug it down," a practice that can result in a sudden surge of caffeine into the bloodstream over the next hour.

 The high caffeine content in coffee occurs naturally, while that found in energy drinks is added artificially. As such, it is subject to further government regulation as a food additive.

And that's what the San Francisco city attorney and many medical advocates are hoping that government regulators will do. Until that happens, we would be wise to regulate our own use of these products.

Dr. Eberhart-Phillips is the former Marin County Public Health Officer, whose column appears every third Monday. He is a specialist in preventive medicine and the author of two books on emerging infectious diseases.